Medical procedures often require the insertion of medical devices such as a catheter or optical fiber into a patient. To properly use such medical devices, it is necessary to be able to navigate the devices through body cavities and channels. Current systems generally employ straight catheters or fibers that are flexible enough to conform to the body cavity in which they are disposed. Navigation is realized by pushing the devices forward or pulling them backward from the proximate end. As the devices are moved, the navigator of the devices must rely solely on the flexibility of the devices to navigate through branches and curves in the body. Another form of catheter, such as that of U.S. Pat. No. 4,802,461, has a controllable flexible tip at the distal end of a straight catheter. Deformation of the tip can be caused through control wires operated at the proximal end.